Apparatus for making frozen drinks

ABSTRACT

The present invention is a frozen drink machine and a method for making frozen drinks from a frozen substance which has been frozen into a block. According to the method of the present invention, a block of frozen substance is held in a vessel while a rotatable blade having features for grinding the frozen substance, and if desirable, for aerating the ground frozen substance, acts on the block, grinding the frozen substance while a heated liquid is simultaneously introduced into the vessel. An apparatus according to the present invention supports a cup containing the frozen substance, and includes a rotatable blade which is lowered into the cup and means for pumping a heated liquid into the cup.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority from divisional U.S. patent applicationSer. No. 08/866,548, filed on May 30, 1997, for “Apparatus and Methodfor Making Frozen Drinks” by James J. Farrell.

FIELD OF THE INVENTION

The present invention relates generally to the field of food processingmethods and equipment, and particularly to apparatuses and methods formaking milkshakes and other frozen drinks.

BACKGROUND OF THE INVENTION

The present invention relates to an improved means of making milkshakesand other frozen drinks. Currently the two commercially prevalentmethods of making milkshakes and other frozen drinks are: 1) placingfrozen ingredients such as ice cream scoops or ice or frozen fruit intoa blending/mixing receptacle, then adding cool liquid such as milk orjuice or water, and then blending them together, or 2) using adispensing freezer of the type in which liquid ingredients areautomatically fed into a freezing cylinder, agitated by a dasher in thecylinder during the freezing operation, and then dispensed when desiredthrough a front discharge valve.

The first method, while delivering an excellent quality milkshake orfrozen drink, takes too much time and labor to be viable in high volumefast-food restaurants, where a major portion of the potential marketlies. The second method, using a dispensing freezer, dominates thefast-food market, yet possesses several serious short-comings. Therequired dispensing freezer equipment is expensive to purchase, and verytime consuming and expensive to clean and maintain. In addition, thequality of product this equipment produces, by its nature, does notrecreate the “old fashioned” style texture that can only be achieved byblending frozen ingredients together with liquid ingredients and thenserving immediately. Consumers do not respond nearly as favorably to thehomogeneous texture produced by the dispensing freezer equipment as theydo to the old fashioned texture, and therefore, these dispensing freezerdrinks do not sell well, holding less than 3% market share of totalrestaurant beverage sales today.

The overall goal of this invention is to enable the creation of aconsumer preferred old fashioned texture milkshake or other frozen drinkthat will fit into the operational constraints of today's high volumefast-food restaurants. In order to meet the operational constraints oftoday's fast-food restaurants this invention was developed to achieveseveral objectives.

One objective is to create a milkshake or other frozen drink in 30seconds or less. In the fast-food market literally every second ofpreparation time is critical. By enabling preparation time to be reducedby even a few seconds, a number of features of this invention aresignificant improvements over the existing art.

Another object of the present invention is to achieve high levels ofwhipping/aeration of the frozen drink, and preferably whipping/aerationof at least 15% of total volume. This level of whipping is important fortwo reasons. First, it is critical to keeping ingredient costs of thisnew method in competitive alignment with milkshakes and frozen drinksproduced by dispensing freezers, which are whipped to this level ofaeration and higher. Second, whipping also substantially improves flavordelivery of a frozen drink by improving a consumer's ability to tastethe drink as their sense of smell senses the frozen drink's aromatrapped inside the tiny bubbles created by the whipping process.

In Applicant's U.S. Pat. No. 5,962,060, the disclosure of which isincorporated herein by reference, a method for making frozen drinks isdescribed which meets the listed objectives. The application describes amethod and apparatus which allows milkshakes and other frozen drinks tobe quickly made by breaking up frozen blocks of ingredients into smallfrozen particles, and combining them with an added liquid. Theingredients to be frozen into frozen blocks are pre-mixed in liquidform, placed into serving cups which are the same serving cups in whichthe finished milkshake or frozen drinks are to be served, and thenfrozen into blocks conforming to the insides of the serving cups andstored.

According to the disclosure, when a milkshake or other frozen drink isto be made, a serving cup containing the frozen block is positioned inthe machine. A rotating blade is lowered into the cup and bores throughthe frozen substance in the cup. Milk or another liquid is added to thecup for blending with the frozen substance, which is broken up intosmall frozen particles by the boring blade. The machine introduces airinto the liquid or the liquid plus frozen particle mixture in order togive the milkshake or frozen drink its proper volume, texture, andflavor delivery.

For certain applications, it may be desirable to use water or anothernon-dairy liquid in the frozen drink making process just described. Ithas been found, however that when a non-dairy liquid is used as theadded liquid in the process, a frozen beverage having a diluted, waterytaste and granular consistency generally results.

Given the desirability of frozen drinks having a full-bodied flavor anda very smooth, “old-fashioned style” consistency, the present inventionis directed to achieving full-bodied flavor delivery from the frozeningredients used, and eliminating the granular consistency which mayresult when non-dairy liquids are used in the frozen drink process.

BRIEF SUMMARY OF THE INVENTION

The present invention is a method for making frozen drinks from a blockof frozen substance, and an apparatus which may be used in carrying outthe method. According to the method of the present invention, a block offrozen substance is held in a vessel while a blade having features forgrinding the frozen substance acts on the block, grinding the frozensubstance while a heated liquid is simultaneously introduced into thevessel. An apparatus according to the present invention supports a cupcontaining the frozen substance, and includes a rotatable blade which islowered into the cup and means for pumping a heated liquid into the cup.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the method according to thepresent invention as carried out using a blender.

FIG. 2 is a perspective view of a milkshake cup according to the presentinvention.

FIG. 3 is a front elevation view of a frozen drink machine according tothe present invention, in which a front panel is removed to expose thecarriage and blade drive assemblies.

FIG. 4 is a side elevation view of the frozen drink machine of FIG. 3.

FIG. 5 is a front elevation view of the frozen drink machine of FIG. 3in which the blending assembly housing has been pivoted to an opencondition to expose the interior of the refrigerator housing and tofurther expose the back side of the blending assembly housing.

FIG. 6A is a front elevation view of a portion of the carriage, thesleeve mounted to the carriage, and the blade shaft extending throughthe sleeve and the carriage. The sleeve and carriage are cut away tomore clearly illustrate the structure of the shaft and the contents ofthe sleeve.

FIG. 6B is a front elevation view, similar to the view of FIG. 6A, inwhich the spring is in a compressed state.

FIG. 7A is a front elevation view of the frozen drink machine of FIG. 3showing the carriage at the end of its downward travel and showing theblade moving downwardly within the serving cup.

FIG. 7B is a front elevation view of the frozen drink machine of FIG. 3showing the carriage and the blade at the ends of their respectivedownward travels.

FIG. 8 is a perspective view of the cup housing according to the presentinvention.

FIGS. 9A and 9B are side views of the cup housing of the frozen drinkmachine of FIG. 3, showing small and large cups, respectively,positioned in the cup housing.

FIG. 10 is a front elevation view, similar to the view of FIG. 3, inwhich the cup support assembly is pivoted into the opened condition.

FIGS. 11A and 11B are a top plan view and a side elevation view,respectively, of a blade according to the present invention.

FIG. 12 is a cross-sectional side view of the blade of FIGS. 11A and11B, taken along the plane designated 12—12 in FIG. 11A.

FIG. 13 is a simplified flow diagram showing the functions of themicroprocessor of the present invention.

DETAILED DESCRIPTION

Generally speaking, the method of making milkshakes and frozen drinksaccording to the present invention allows milkshakes and other frozendrinks to be quickly made by breaking up frozen blocks of ingredientsinto small frozen particles, and combining them with an added heatedliquid. The ingredients to be frozen into frozen blocks are pre-mixed inliquid form, and then frozen into blocks and stored. The ingredients maybe frozen into single-serving blocks which may be removed from thefreezer as needed for making individual frozen drinks. Alternatively,the ingredients may be frozen into serving cups which are the sameserving cups in which the finished milkshake or frozen drinks are to beserved.

During the frozen drink making process, the frozen block is acted uponby a rotating blade, which grinds the frozen substance into small frozenparticles. Heated liquid is added to the frozen block for blending withthe frozen particles. The blade may also introduce air into the liquidor the liquid plus frozen particle mixture in order to improve themilkshake or frozen drink's volume, texture, and flavor delivery.

For the rest of this detailed description, the details of the inventionwill be provided with milkshakes as the end-product being produced,though it is to be understood that end-products such as smoothies or avariety of other frozen drinks can be made by the machine and methoddescribed herein.

In its simplest form, the method of the present invention may be carriedout using a conventional blender, which, like blender 300 of FIG. 1,includes a blending chamber 302 and a rotatable blade 304.

First, ice cream mix is combined with concentrated milk; that is, milkwith a portion of its water content evaporated. A preferred mixtureincludes typical ice cream mix as specified in the following chart,combined with milk which has been concentrated to one half its beginningweight through evaporation as also specified, resulting in the combinedproduct as specified.

Sample Formula Specification Table Ice Cream Mix + Concentrated Milk =Combined Product Weighted Ounces 7 3 10 Percentages by Weight: Milk Fat10.0% 7.0% 9.1% Non-Fat Milk Solids 12.0% 17.0% 13.5% Sugar 15.0% 0.0%10.5% Emulsifiers and Stabilizers 0.3% 0.0% 0.2% Water 62.7% 76.0% 66.7%TOTAL 100.0% 100.0% 100.0%

This mixture is then frozen into an ice cream like frozen substance byincorporating air as it is agitated and frozen, such that the finishedproduct is approximately 35% air by volume. Naturally, the ingredientsand quantities may vary without departing from the scope of the presentinvention. Preferably, the mixture is frozen into single servingquantities of 13 fluid ounces for a 16 fluid ounce milkshake.

Referring to FIG. 1, when a milkshake is to be made, a scoop or block306 of this ice cream like frozen substance is positioned in theblending chamber 302. A measured quantity of heated water is added tothe blending chamber. The blender is switched to the “on” condition tobegin rotation of the blade 304. The rotating blade 304 grinds throughthe frozen substance in the cup and blends the added heated water withthe frozen substance as it is broken up into small frozen particles bythe blade.

If unheated tap water were added rather than heated water, even if themilk portion of the frozen ingredients had been more greatlyconcentrated to compensate for the greater quantity of unheated tapwater to be added, the amount of added water necessary to achieve theproper thickness of milkshake would cause the milkshake to have a waterytaste. Moreover, a portion of the added unheated tap water would freezeinto small ice granules during blending, causing the resulting milkshaketo lack the smooth texture that is most desirable for milkshakes.

It has been found that this phenomenon can be eliminated if the water isheated before it is introduced into the blending chamber 302. By heatingthe water, three improvements are achieved simultaneously. First, theamount of water necessary to achieve the proper thickness of finishedfrozen beverage is greatly reduced. For instance, to achieve the properthickness of finished frozen beverage, a 13 fluid ounce frozen block ofice cream like frozen substance requires the addition of 6 fluid ouncesof water at the typical 50° F. achieved by using ambient tap water, butonly 3 fluid ounces of water heated to 170° F. This reduction inquantity of added water impacts the watery taste problem becauseapproximately half as much water is added, directly resulting in a lesswatery, more full-bodied taste. Second, as the hot water is cooled fromits elevated temperature by the frozen substance during mixing, the hotwater proportionally causes more of the frozen substance to be meltedand incorporated into the added water, resulting in a greaterconcentration of the ingredients from the frozen substance being mixedinto the liquid phase of the frozen beverage. The liquid phase of afrozen beverage has a much greater impact on taste than the frozen phasebecause it is able to be sensed by the taste buds more readily. Thus,this higher concentration of frozen ingredients melted into the liquidphase also helps very substantially to solve the watery taste problem.Third, because of the greater concentration of frozen ingredients meltedinto the liquid phase of the frozen beverage, the freezing point of theliquid phases is depressed further by the use of heated water. Thetemperature of the liquid in a finished milkshake is typically 29° F.This is due to its concentration of sugars, which depress the freezingpoint from 32° F. for pure water. When typical 50° F. tap water is used,the concentration of sugars combining with the water in the liquid phaseare insufficient to depress the freezing point of the added water to the29° F. level, and the frozen ingredients cause a portion of the addedwater to freeze into small crystals. This freezing causes a granulartexture. When heated water is used, the concentration of sugars in theliquid phase reaches a level adequate to depress the freezing point ofthe liquid phase to a level where any appreciable freezing of the waterfrom the liquid phase into ice crystals is eliminated. This eliminatesthe granular texture problem.

An alternative embodiment of an apparatus for use in carrying out themethod of the present invention is shown in FIGS. 3 through 13. While ablender works well at carrying out the method, the apparatus of FIGS. 3through 13 is more appropriate for commercial food service in that iteliminates much of the time and labor needed using the blender method.In addition, it has the added advantage of being able to incorporate airinto the frozen beverage during the mixing process. This ability toincorporate air allows the use of a frozen block of ingredients which isnot pre-aerated, further simplifying the preparation of the frozeningredients.

Cup and Ingredients

A serving cup 200 of the type which maybe used in the method andapparatus according to the present invention is shown in FIG. 2. Theexterior surface of the cup 200 includes a plurality of ridges 202.

When ready for use in the machine according to the present invention,the cup 200 contains milkshake ingredients which are frozen into a block204 which conforms to the shape of the cup. The block 204 includes anupper surface 206. The frozen substance preferably comprises all theingredients required to make a milkshake, with the exception of the airand a portion of the water. The Sample Formula Specification Table abovelists preferred quantities for ingredients, with the exception of theair. Air is an important ingredient in a finished milkshake because itgives the milkshake its proper volume and texture, and improves flavordelivery. Specifically, a cup which will yield a sixteen fluid ouncevolume milkshake typically contains a frozen block 204 of approximatelyten fluid ounces of combined product, but with no air incorporated. Thisten ounces of combined product consists of seven ounces of standard icecream mix combined with six ounces of milk, as would be used in aconventional old-fashioned milkshake, except that the six ounces of milkhas been reduced to three ounces of concentrated milk by evaporating outthree ounces of water. This three ounces of water which has beenevaporated out will be added back into the milkshake mixture later asthe heated water during mixing in the frozen drink machine 10. It shouldbe pointed out that this approach differs from placing ice cream or anice cream like frozen substance, as used in the earlier conventionalblender example, in the cup because they, by definition, contain airwhich is incorporated during freezing. For instance, the ice creamtypically used in old-fashioned scooped type milkshakes-typicallycontains approximately 35%-50% air by volume. At the completion of themilkshake making operation, the ten fluid ounces of combined productwill have had three fluid ounces of heated water added, for a sub-totalof thirteen fluid ounces, plus three fluid ounces of air incorporated bythe whipping action of the rotating blade, resulting in the desiredsixteen fluid ounce, full-bodied, smooth textured finished milkshake.

The ingredients are frozen into the cup 200 and form a block of frozensubstance that typically fills the cup by approximately 60% of its totalvolume. As will be appreciated below, the full volume of the cup is usedto contain milkshake once the heated liquid and air are introduced intothe cup during a milkshake making operation.

Milkshake and Frozen Drink Machine

Referring to FIGS. 3 and 4, the frozen drink machine 10 according to thepresent invention is comprised generally of a rear housing 12, ablending assembly housing 14, and a cup housing 16.

Referring to FIG. 5, the rear housing 12 includes a compartment 18having a shelf 20. Above the shelf 20, compartment 18 contains a liquidreservoir 22 for containing the liquid (preferably water) which is addedto the cup during milkshake processing. The liquid may be pumped intothe reservoir 22 by an external source or it may be installed inreplaceable containers. Reservoir 22 may be a heated vessel similar to aconventional hot water heater or it may be configured to receive heatedliquid from an external source. Water in reservoir 22 is stored at anelevated temperature well above room temperature, preferablyapproximately 100° F.-180° F. and most preferably 170° F.

A tube 24 extends from liquid reservoir 22 and extends through aperistaltic pump 26. Tube 24 has an open end 27 positioned withinblending assembly housing 14.

Rear housing 12 includes a base portion 29 which lies below the rearcompartment 18. A block 31 (FIGS. 4 and 5) extends from the base portion29 and supports a pair of limit switches 33 a, 33 b.

A microprocessor 35 (FIG. 5) is contained within the base portion 29 ofthe rear housing 12. As will be discussed in detail below, themicroprocessor 35 receives information from the limit switches 33 a, 33b and other sensors which monitor operation of the milkshake machine,and manages the operation of the milkshake machine. A starting switch 37is located on the front of the rear housing 12 and is interfaced withthe microprocessor 35 to deliver starting signals to the milkshakemachine when triggered by a user.

Referring to FIG. 4, blending assembly housing 14 is hinged to the rearhousing 12 so that blending assembly housing 14 can be pivoted into theopen position shown in FIG. 5 in order to allow the water supply (if areplaceable source is used) to be replaced. A support frame 28 ismounted to the blending assembly housing 14. Upper and lower supportmembers 30 extend laterally from support frame 28.

Referring to FIGS. 3 and 4, two motors are mounted to frame 28 withinthe housing 14: a carriage motor 32 and a blade motor 34. Carriage motor32 includes a shaft 36 which spins when the motor is activated. Shaft 36is coupled to a first pulley 38 and a belt 39 is driven by first pulley38. Carriage motor 32 is preferably a stepper motor capable of 1500 RPMand 140 ounce-inches of torque.

Blade motor 34 is preferably a one horsepower motor capable of up to3400 revolutions per minute. It includes a rotatable shaft 40 which iscoupled to a second pulley 42 such that activation of the blade motor 34results in rotation of the second pulley 42. A belt 43 is driven bysecond pulley 42.

A carriage 44 is located within the housing 14. An elongated rod 46(FIG. 3) extends through a bore 48 in the carriage 44 and is fixed tothe support members 45. Rod 46 is secured to the blending assemblyhousing 14 by a number of mounting blocks 50. The bore 48 isproportioned such that the carriage 44 can slide easily along the rod46, and linear bearings (not shown) are pressed into the ends of bore 48to aid the sliding motion.

Referring to FIG. 3, carriage 44 includes a laterally extending member52 having a bore 54. A ball nut 56 is secured within the bore 54, and avertical screw drive 58 extends through the ball nut 56. The screw drive58 is mounted to the support frame 28 by a pair of mounting members 60.

A third pulley 61 is attached to one end of screw drive 58. Belt 39 iscoupled to pulley 61 such that rotation of pulley 38 results incorresponding rotation of third pulley 61. Thus, activation of carriagemotor 32 results in rotation of screw drive 58. When screw drive 58 isrotated in this manner, ball nut 56 is caused to travel vertically alongthe screw drive 58 and to thereby move the carriage 44 vertically upwardor downward, depending on the direction in which the screw drive isrotating.

Carriage 44 is a substantially rectangular frame having a rectangularcenter opening 62. A bore 64 extends through the upper end of thecarriage 44 and into the opening 62. A splined spindle shaft 66 isslidably disposed in the bore 64. Splined shaft 66 extends through abearing 68 which is mounted to the support frame 28 by a support 69. Afourth pulley 71, which is internally splined, is attached to thebearing 68 and belt 43 is coupled to fourth pulley 71. Thus, rotation ofsecond pulley 42, such as by activation of blade motor 34, causesresultant rotation of splined fourth pulley 71.

During rotation of splined pulley 71, the splines in splined shaft 66and splined pulley 71 are rotationally engaged with one another suchthat rotation of splined pulley 71 causes rotation of splined shaft 66.This engagement, however, does not prevent the splined shaft 66 fromsliding vertically within the splined pulley 71 and bearing 68 duringvertical movement of the carriage 44.

Splined shaft 66 includes a smooth section 70. A collar 72 (FIGS. 6A and6B) surrounds and is fixed to the smooth section 70 of shaft 66. Shaft66 further includes a tapered section 74 and a blade 76 attached to thetapered section 74.

Referring to FIG. 6A, smooth section 70 of shaft 66 extends through asleeve 78 mounted to the carriage 44 within the opening 62 (opening 62shown in FIG. 2). A shoulder 82 is formed at the top of sleeve 78.

A compression spring 80 surrounds the shaft section 70 and is housedwithin the sleeve 78. Spring 80 has a first end 84 which abuts theshoulder 82 and a second end 86 which abuts collar 72. When carriage 44advances downwardly in the direction indicated by arrow Al, and blade 76reaches the surface 206 of the frozen substance 204 in the cup, spring80 becomes compressed between shoulder 82 and collar 72 as indicated inFIG. 6B. Gradually, shaft 66 slides downwardly, as indicated by arrow A2in FIG. 6B, through the sleeve 78 until spring 80 returns to its relaxedcondition shown in FIG. 6A.

Referring to FIGS. 7A and 7B, an optical detector 88 is mounted to thetop of carriage 44. Optical detector includes a light source 90 and areceiver 92 which detects light emitted by light source 90. Opticaldetector 88 is positioned to detect whether the upper end of splinedshaft 66 is extending above the carriage 44. When the upper end of theshaft 66 extends above the carriage 44, receiver 92 is prevented fromreceiving light emitted by light source 90. When the carriage 44 islowered and the upper end of the splined shaft 66 can be detected by theoptical detector 88, it indicates that the blade 76 has not yet reachedthe bottom of the serving cup 200 which contains the milkshakeingredients.

Optical detector 88 is electronically coupled to microprocessor 35 (FIG.5). When the blade 76 reaches the bottom of the serving cup 200 duringuse of the milkshake machine, this information is received by themicroprocessor 35 and used to control the milkshake making operation aswill be discussed below.

Referring to FIGS. 4, 5 and 8, support frame 28 has a lower portion 94positioned above the cup housing 16. Lower portion 94 includes arecessed section 96 which, when the blending assembly housing 14 ispivoted to the closed condition shown in FIG. 4, faces the portion ofthe rear compartment 18 which lies below shelf 20.

Recessed section 96 is bounded by three side walls 98, a top wall 100(FIG. 5), and a bottom wall 102. Openings 104 a, 104 b shown in FIG. 4,are formed in top and bottom walls 102. These openings permit the blade76 to extend into the recessed section 96 and to pass from the recessedsection into the cup 200.

A solenoid latch 103 having a plunger 105 (FIGS. 9A and 9B) is attachedto lower portion 94 of housing 14. The solenoid latch 103 works in aconventional manner. Plunger 105 is spring biased in the elevatedcondition shown in FIG. 10. When solenoid latch 103 is energized,plunger 105 slides vertically downward to the latched position shown inFIGS. 9A and 9B.

Referring to FIG. 10, cup housing 16 includes a side section 106 whichis hinged to the rod 46. Cup housing is pivotable about the rod 46between the closed position shown in FIG. 3 and the open position shownin FIG. 10. A handle 107 is provided to permit the cup housing to beeasily pivoted between the closed and open positions. When the solenoidplunger 105 is in the latched position shown in FIG. 9A, it prevents thecup housing from being moved to the open position.

Referring to FIG. 10, cup housing 16 includes a tray 108 which isprovided with a cut-out 110 for receiving a serving cup 200. The portion114 of the cup housing 16 above the tray is open. Cup housing 16 furtherincludes an outer wall 112 which, when the cup housing is in the closedposition, causes the cup 200 to be enclosed between the outer wall 112and base portion 29 of rear housing 12. Moreover, and as best shown inFIGS. 9A and 9B, when the cup housing 16 is in the closed condition, theblock 31 which is attached to rear housing 12 extends into the openportion 114 of the cup housing 16. The wall 112 and the block 31 areimportant because they prevent access to the cup during the processingcycle, when it would be very dangerous to disturb the cup due to thesharp blade spinning at high RPM inside the cup.

Referring again to FIGS. 9A and 9B, when a cup is positioned in the cuphousing and the cup housing placed in the closed condition, the cupdepresses at least one of the limit switches 33 a, 33 b. A short cup 200b, shown in FIG. 9A, will depress only lower limit switch 33 b, whereasa tall cup 200 a, shown in FIG. 9B will depress both lower and upperlimit switches 33 a, 33 b. The switches 33 a, 33 b provide a means bywhich the presence of a cup in the cup housing may be detected. As willbe described in detail below, when at least one of the switches 33 a, 33b is closed, the microprocessor activates solenoid latch 103, causingthe cup housing 16 to be locked in the closed condition and generatesstarting signals which cause the frozen drink making cycle to begin.

The limit switches 33 a, 33 b also deliver information to themicroprocessor 35 (FIG. 5) concerning the size of the cup which ispositioned in the cup housing. As detailed below, this will ensure thatthe appropriate quantity of liquid is delivered into the cup for thesize milkshake which is to be made. Also, because the surface 206 (FIG.2) of the frozen block 204 is lower in a smaller cup than in arelatively larger cup, the microprocessor can ensure that the blade 76is lowered to the proper height before it is caused to begin spinning.

Referring to the perspective view of FIG. 8, cut-out 110 includes ridges116 around its perimeter. These ridges are designed to engage with likeridges 202 on the outside surface of the serving cup 200. This preventscup 200 from rotating within the cut-out 110 as the rotating bladeadvances through the frozen substance.

Blade

FIGS. 11A and 11B are top and side views, respectively, of blade 76.Blade 76 is preferably a 2.5 inch diameter stainless steel blade havinga circular shape and a thickness of approximately 0.080 inches.Three-eighth inch diameter holes 118 a, 118 b and 118 c are spaced 120°apart rotationally and at specific radiuses from the center of the bladesuch that as the blade makes one complete rotation, the entire surfacearea of the frozen substance will have been passed over by three holes.Holes 118 a are centered 0.041 inches from the blade's center, and holes118 b and 118 c are spaced 0.062 inches and 0.083 inches from theblade's center respectively. Depressed regions 120, best shown in thecross section view of FIG. 12, are formed immediately adjacent to eachof the holes, located on their trailing edge as the blade rotates. Theseregions are depressed by 0.080 inches. The holes and the depressedregions are arranged such that as the blade 76 is rotated and advancedinto the frozen substance in the cup 200 (FIG. 2), the holes 118 a-c anddepressed regions 120 grate through the frozen substance much like thegrating action of a cheese grater. It should be appreciated that theblade of FIG. 11A is configured such that clockwise rotation of thisblade produces the desired grating effect. This arrangement alsoprovides for easy manufacture in a stamping operation, and maintains themechanical strength of the blade so that its outside edges are notdeflected upward by the force of the frozen substance being boredthrough. Other arrangements with differing size or shaped holes willalso work well.

Three waves are formed in the blade. As shown in FIGS. 11A and 12, eachof the waves 122 includes a center crease 124 which is elevated abovethe plane of the blade and side creases 126 which lie in the plane ofthe blade. The creases 124 and 126 are approximately ½ inches in lengthand extend radially from the perimeter of the blade. A distance alongthe perimeter of the blade of approximately ½ inch separates each pairof side creases 126. During high speed rotation of the blade, the waves122 increase the whipping effect of the blade by causing an alternatelyhigh and low pressure zone at the blade's edge, creating turbulenteddies which cause a whipping effect.

Three pairs of cutouts 128 are formed along the perimeter of the blade76, spaced 120° from each other. Each pair includes a first cutout whichhas a depressed trailing edge 130 and a second cutout which has anelevated trailing edge 132. During a milkshake making operation, thetrailing edge 130 is depressed to act as a grating surface to borethrough the frozen substance at the outermost radius of the blade. Thetrailing edge 132 is elevated to act as a inverted ramped surface toforce milkshake downward in the cup and thereby minimize the amount ofmilkshake that is driven up the interior walls of the cup by centrifugalforce. Moreover, by directing milkshake ingredients above the blade,which are carried to the outer edge of the blade by centrifugal force,to then be forced downward and under the blade as the rotating blademoves upward, the elevated trailing edge 132 helps prevent the bladefrom carrying ingredients up and out of the cup as the blade is liftedfrom the cup.

Operation

Operation of the frozen drink machine according to the present inventionwill next be described.

First, cup housing 16 is pivoted to the opened condition shown in FIG.10 and a cup 200 containing the frozen substance 204 is positioned inthe cut-out 110. Cup housing 16 is then pivoted to the closed positionshown in FIG. 3.

Next, carriage motor 32 is activated. Activation of carriage motor 32causes rotation of carriage motor shaft 36 and pulley 38, and throughbelt 39 further causes rotation of pulley 61 which is attached to thevertical screw drive shaft 58, causing it to rotate. Counterclockwiserotation of screw drive shaft 58, when viewed from the top, causescarriage 44 to advance vertically downward as indicated by arrow A3 inFIG. 3. Carriage 44 has spindle shaft 66 mounted to it such that whencarriage 44 advances vertically downward, spindle shaft 66 advancesdownward as well, with one exception which will be explained shortly. Asblade 76, attached to the bottom of spindle shaft 66, approaches thesurface 206 of the frozen substance 204, blade motor 34 is activatedcausing rotation of pulley 42, and through belt 43, rotation of pulley71 which is attached to spindle shaft 66, causing it and blade 76 tospin. Downward travel of carriage 44 continues and blade 76 makescontact with the surface 206 of the frozen substance and begins boringdown through it.

At the time boring begins, the liquid pump 26 is activated and beginspumping heated liquid into the cup through tube 24 for mixing andwhipping with the small frozen particulate being created by the boringaction of the blade. Approximately three fluid ounces of liquid at anelevated temperature of approximately 100-180° F., but most preferably170° F., is pumped into the cup over a period of approximately three tofive seconds, depending on the desired consistency of the finishedmilkshake. The elevated temperature of the water results in a morefull-bodied taste and prevents the water from forming into ice crystalsas it is blended with the ingredients contained in the cup 200, asdescribed earlier.

The downward travel of the carriage 44 is generally driven at a ratefaster than the blade 76 can bore through the frozen substance in thecup. This disparity in downward travel rates causes the downward travelof the spindle shaft 66, to which the blade 76 is attached, to be slowerthan the downward travel of carriage 44. This forces the spindle shaft66 to move upward within its mountings on the carriage 44 and for spring80 to be compressed as shown in FIG. 7A. The carriage 44 is driven toits lowest most point of travel, as shown in FIG. 7B, and then thecarriage motor 32 is deactivated.

The blade 76 continues to grate and blend the frozen substance 204within the cup 200 as it moves downward in the cup, driven by thegradual relaxation of the compressed spring 80 (FIGS. 6B and 7A) actingon spindle shaft 70. When the optical detector 88 senses that thespindle shaft has progressed all the way to the bottom of the cup asshown in FIG. 7B, the boring stage of the process is complete.

The reason for this spring release arrangement is to allow for a highrate of travel speed of the carriage 44 from its uppermost position atthe beginning of the cycle to the bottom of its travel. This isadvantageous because it allows the blade 76 to bore as quickly as thefrozen substance will allow. Softer frozen substances can be boredthrough more quickly. Without this spring release arrangement, timewould be wasted as the carriage 44 would have to be driven downward asslowly as the hardest frozen substance could be bored through in orderto be sure the blade motor 34 is not stalled out by an excessive torquerequirement to continue the blade's rotation. An additional advantage isthat the exact rotational speed for the carriage motor 32, driving thedownward travel of the carriage during boring, becomes less critical.This simplifies the controls required for this motor.

Given these two advantages of the spring release, it can be appreciatedthat the same advantages could be accomplished through a variety ofother means, including placing the spring mechanism on the screw driveshaft or its mountings rather than on the spindle shaft, or placing aslip clutch in the connection of the carriage motor to the screw driveshaft which would slip as the spindle and carriage's downward travel wascaused to slow down by the resistance of the boring blade against thefrozen substance.

With the boring stage complete, as signaled by the optical detector 88when the blade 76 reaches the bottom of the cup, the carriage motor 32is caused to reverse polarity and is activated to begin to move thecarriage, and with it, the spindle drive shaft and blade, upward asindicated by arrow A4 in FIG. 7B. At this point in the process, therotating blade 76 acts as a mixing and whipping agitator, with theimportant feature of being formed such that its slim cross-sectionalprofile does not cause excessive rotation of the entire contents of thecup. The carriage motor 32 raises the carriage, and with it, therotating blade up through the milkshake, completing the mixing andwhipping of the frozen particulate and heated liquid into a milkshake asit travels vertically through it.

Some formulations of milkshake benefit from a second vertical pass ofthe mixing/whipping blade through the milkshake, in which case themixing blade's vertical travel is stopped one inch below the surface 210of the milkshake 212 (labeled in FIG. 7B), and the polarity of thecarriage motor 32 is again reversed, and the blade 76 is moved back downto the bottom of the cup. Upon reaching the bottom, the polarity of thecarriage motor 32 is again reversed, and the blade is moved back upwardin the cup 200 to a point one inch below the surface 210 of themilkshake 212.

With the mixing and whipping process complete, and the blade reachingthe point one inch below the surface 210 (FIG. 7B) of the milkshake 212,the blade motor 34 is deactivated and a braking force applied to theblade motor to slow its rotational speed. This slowing of the blade'srotational speed prevents splattering of milkshake out of the cup as theblade breaks through the surface 210 of the milkshake 212. With therotation slowed, the carriage moves up to a point where the blade isapproximately one half inch above the surface 210 of the milkshake 212,but still below the top lip of the cup, and stops momentarily. With thecarriage stopped momentarily, the blade motor is reactivatedmomentarily, causing the blade to spin and fling any remaining milkshakematerial off the blade and back into the cup below its upper lip. Aftera momentary spinning of approximately one half second, the blade motor34 is deactivated, and the carriage motor 32 is reactivated to bring thecarriage and blade upward to its original position above the cup. Atthis point, the process is complete and the cup can be removed forserving by opening cup housing 16 and removing cup 200 from the recess110.

As shown in FIG. 3, when the carriage 44 and blade 76 are in theiroriginal positions, the blade 76 and the narrow portion 75 of shaft 70are disposed within recessed section 96 of the housing 14.

Microprocessor Control

The functions of the microprocessor 35 in controlling the frozen drinkmaking operation will next be discussed with reference to FIG. 13. Afrozen drink making operation is commenced at step 300 when a userpresses the start button 37 (FIG. 3). Next, the microprocessor 35detects whether at least one of the limit switches 33 a, 33 b (FIGS. 9Aand 9B) is closed, which indicates the presence of a cup 200 in the cuphousing 16. If a limit switch is closed, the microprocessor 35 causesactivation of the solenoid latch 103, step 304, such that plunger 105moves to the latched condition shown in FIG. 9A to latch the cup housing16. If a limit switch is not closed, the microprocessor terminates themilkshake making procedure or it may alternatively continue monitoringthe limit switches for a predetermined period of time.

Next, at step 306 the microprocessor 35 determines whether a tall cup200 a (FIG. 9B) or a short cup 200 b (FIG. 9A) is positioned in the cuphousing 16 by determining whether only one limit switch 33 b is closed,indicating a small cup, or whether both limit switches 33 a, 33 b areclosed, indicating a large cup.

At step 308, the microprocessor retrieves certain cup size-dependentvalues from look up tables stored in its memory. For example, because alarger quantity of added liquid is needed for a large milkshake than fora small milkshake, one of the stored values is the length of time forwhich the peristaltic pump 26 will be made to pump heated liquid intothe cup 200. The other stored values include (1) those indicating thedistance to be traveled, or the amount of time for travel, by thecarriage 44 to position the blade 76 at the surface 206 of the frozenblock 204, which will be higher for a large cup than it will for a smallcup; (2) those indicating the distance to be traveled (or the amount oftime for travel) by the carriage from the surface 206 of the frozenblock 204 to the bottom of the cup; (3) those indicating the distance tobe traveled (or the amount of time for travel) by the carriage to liftthe blade from the milkshake to a height just below the upper surface210 (FIG. 7B) of the milkshake 212; and (4) those indicating thedistance to be traveled (or the amount of time for travel) by thecarriage to lift the blade from the milkshake to a height just above theupper surface 210 of the milkshake 212.

During steps 310 through 316, the stored values retrieved at step 308are used to generate control signals which control the carriage motor32, blade motor 34, and peristaltic pump 26. Specifically, themicroprocessor at step 310 instructs the carriage motor 32 to advancethe carriage by the appropriate number of steps to position the blade 76just above the surface 206 of the frozen block. At step 312 themicroprocessor further directs the carriage motor 32 to advance thecarriage 44 by the appropriate number of steps which will cause theblade 76 to move to the bottom of the cup (step 314). At step 316, themicroprocessor delivers control signals to cause the peristaltic pump 26to pump heated liquid into the cup through opening 37 for the amount oftime which will deliver the proper quantity of heated liquid into thecup.

At step 318, the microprocessor looks to the optical sensor 88 andawaits a signal from the optical sensor indicating that the blade 76 hasreached the bottom of the cup (FIG. 7B). When the blade 76 has reachedthe bottom of the cup, the microprocessor instructs (steps 320) thecarriage motor 32 to move the carriage 44 vertically upward by an amountwhich will position the blade 76 approximately one inch below themilkshake surface 210.

Next, the microprocessor directs the blade motor 34 (step 322) todeactivate and thereby slows the rotation of the blade 76. As describedabove, this prevents splattering of milkshake out of the cup as theblade breaks through the surface 210 of the milkshake 212.

Next, at step 324, the carriage motor 32 is caused to advance thecarriage 44 such that the blade 76 is approximately one half inch abovethe surface 210 of the milkshake 212, but still below the top lip of thecup 200. With the carriage stopped momentarily, the microprocessorreactivates the blade motor 34 for approximately 0.5 seconds (step 326),causing the blade to spin and fling any remaining milkshake ingredientsoff the blade and back into the cup below its upper lip. At step 328,which occurs after the reactivation of the blade motor 34, the carriagemotor 32 is instructed to move the carriage 44 and blade 76 into theiroriginal positions above the cup 200. Finally, at step 330, themicroprocessor 35 causes deactivation of the solenoid latch 103, causingplunger 105 to move to the unlatched position shown in FIG. 10, allowingthe cup housing 16 to be opened by a user.

The present invention has been described with respect to twoembodiments, one which utilizes a blender and another which utilizes afrozen drink machine. It should be appreciated, however, that manymodifications may be made to the described embodiments without departingfrom the scope of the invention. For example, the method as describedwith respect to each embodiment maybe carried out using a frozensubstance that is pre-aerated or one that is not pre-aerated.Additionally, the method of the invention may be practiced usingequipment other than that described herein. Accordingly, Applicant'sinvention should be limited only in terms of the appended claims andshould not be restricted by the described embodiments.

What is claimed is:
 1. An apparatus for making a frozen drink from ablock of frozen substance in a cup, the substance frozen tosubstantially conform to the interior of the cup, and the cup having avertical axis, wherein the apparatus comprises: a cup support forreceiving the cup and inhibiting rotation of the cup; an agitator which,when a cup containing a block of frozen substance is positioned on thecup support, is extendable coaxially into the cup to grind the block offrozen substance in the cup into a ground frozen substance; and a liquiddispenser which is configured to direct heated liquid into the cup inthe cup support.
 2. The apparatus of claim 1 wherein the agitatorcomprises a rotatable blade assembly aligned for selected coaxialextension into a cup positioned in the cup support.
 3. The apparatus ofclaim 2, and further comprising: an initiation switch; a controller forgenerating up and down blade movement control signals and blade rotationcontrol signals; a slidable and rotatable shaft attached to the bladeassembly and moveable between upper and lower positions corresponding toupper and lower blade positions; and first and second motors coupled tothe shaft, the first motor responsive to the blade movement controlsignals to move the shaft between the upper and lower positions, thesecond motor responsive to the blade rotation control signals to rotatethe blade assembly, the controller responsive to activation of theinitiation switch to allow the blade assembly to rotate and to belowered into a cup when a user activates the initiation switch.
 4. Theapparatus of claim 3, further comprising: a cup sensor for detecting thepresence of a cup in the cup support and for producing an output,wherein the controller is responsive to the output of the cup sensor toallow the blade assembly to rotate and to be lowered into a cup when acup is detected in the cup support.
 5. The apparatus of claim 1 whereinthe liquid dispenser directs heated liquid into the cup during at leasta portion of the grinding of the frozen substance by the agitator. 6.The apparatus of claim 5 wherein the heated liquid and the agitatorsimultaneously engage the block of frozen substance in the cup.
 7. Theapparatus of claim 1 wherein the agitator and cup are moveable relativeto one another between first and second positions, the first positionhaving the agitator within the cup and in contact with the block offrozen substance in the cup and the second position having the agitatorspaced from the cup.
 8. The apparatus of claim 7, and further comprisinga process controller operable for effecting movement between the firstand second positions.
 9. The apparatus of claim 1, and furthercomprising a heater which heats the liquid to at least approximately100° F.
 10. The apparatus of claim 9 wherein the liquid is heated to atleast approximately 170° F.
 11. The apparatus of claim 10 wherein theliquid is heated to at least approximately 180° F.
 12. The apparatus ofclaim 1 wherein the dispenser directs a predetermined amount of heatedliquid into the cup in the cup support.
 13. The apparatus of claim 12wherein the predetermined amount of heated liquid is about 3 ounces. 14.The apparatus of claim 12 wherein the ratio of the predetermined amountof heated liquid to frozen substance in the cup, by volume, is about3:10.
 15. The apparatus of claim 12 wherein the ratio of thepredetermined amount of heated liquid to a size of the cup, by volume,is about 3:16.
 16. The apparatus of claim 1 wherein the volume of theblock of frozen substance in the cup is approximately 60% of the totalvolume of the cup.
 17. The apparatus of claim 1 wherein the dispenserdirects heated liquid into the cup in the cup support for apredetermined time period.
 18. The apparatus of claim 17 wherein thetime period is from approximately three to approximately five seconds.19. The apparatus of claim 1 wherein the dispenser begins directingheated liquid into the cup approximately when grinding of the frozensubstance in the cup begins.
 20. The apparatus of claim 1 wherein thedispenser begins directing heated liquid into the cup approximately whenthe agitator first contacts the block of frozen substance in the cup.21. The apparatus of claim 1 wherein the agitator includes an aeratorfor causing air to be incorporated into the ground frozen substance bythe rotatable blade.
 22. The apparatus of claim 21 wherein the ratiobetween the volume of incorporated air and the total volume of thefrozen drink is about 3:16.
 23. The apparatus of claim 1, and furthercomprising: a cup sensor for detecting a characteristic of a cup in thecup support and for producing an output corresponding to thecharacteristic of the cup; and a controller for generating a processcontrol signal which corresponds to the output produced by the cupsensor.
 24. The apparatus of claim 23 wherein the characteristic is thesize of the cup.
 25. The apparatus of claim 24, wherein the liquiddispenser is responsive to the process control signal to a dispense avolume of liquid into the cup, the volume corresponding to the size ofthe cup.
 26. The apparatus of claim 24, and further comprising: anagitator assembly being responsive to the process control signal to movethe agitator vertically, the extent of movement corresponding to thesize of the cup.
 27. The apparatus of claim 1, and further comprising:an enclosure which encloses the cup in the cup support so that the cupis inaccessible during grinding of the frozen substance therein by theagitator.
 28. The apparatus of claim 27, and further comprising: anenclosure sensor for detecting whether the enclosure is in an open orclosed position and for producing an output indicating whether theenclosure is in an open or closed position; and a controller forgenerating agitator control signals, the controller being responsive tothe enclosure sensor output, the controller allowing for agitatoroperation only if the sensor output indicates that the enclosure is in aclosed position.
 29. The apparatus of claim 28 wherein agitatoroperation includes extending the agitator coaxially down into the cupand retracting the agitator coaxially up relative to the cup.
 30. Theapparatus of claim 29 wherein the agitator includes a blade, and whereinoperation of the agitator further includes rotating the blade.
 31. Theapparatus of claim 30 wherein the agitator is movable down and up asecond time during grinding of the frozen substance.
 32. The apparatusof claim 31 wherein the agitator is movable coaxially up out of the cup.33. The apparatus of claim 1, and further comprising an enclosure whichencloses the cup in the cup support so that the cup is inaccessibleduring dispensing of the heated liquid into the cup.
 34. An apparatusfor making a milkshake or smoothie in a cup containing milkshake orsmoothie ingredients frozen into a block which conforms to an interiorshape of the cup, the apparatus comprising: a cup holder fornon-rotatably receiving the cup, the cup having a vertical axis; arotatable blade aligned relative to the cup holder to have a firstraised position remote from an open top end of the cup and a secondlowered position wherein the blade is in engagement with the ingredientsinside the cup, the movement of the blade being along the vertical axisof the cup; a mix motor operably coupled to the blade to rotate theblade; a drive motor operably coupled to change the relative blade andcup positions between the first and second positions; a source of liquidheated to at least approximately 100° F.; and a liquid dispenserdisposed over an opening at a top end of the cup in the cup holder, thedispenser being in fluid communication with the source and aligned foradding a predetermined portion of the heated liquid into the cup to bemixed with the ingredients therein by the rotatable blade.
 35. Theapparatus of claim 34 wherein the rotatable blade is in the loweredposition when the heated liquid is added.
 36. The apparatus of claim 34wherein the liquid is heated to at least approximately 170° F.
 37. Theapparatus of claim 34 wherein the dispenser begins adding heated liquidinto the cup approximately when rotation of the blade begins.
 38. Theapparatus of claim 34, and further comprising: an enclosure whichencloses the cup in the cup holder so that the cup is inaccessibleduring mixing of the liquid and the frozen ingredients therein by therotatable blade.
 39. The apparatus of claim 38, and further comprising:an enclosure sensor for detecting whether the enclosure is in an open orclosed position and for producing an output indicating whether theenclosure is in an open or closed position; and a controller forgenerating blade operation signals, the controller being responsive tothe enclosure sensor output, the controller allowing for blade operationonly if the sensor output indicates that the enclosure is in a closedposition.
 40. The apparatus of claim 34, and further comprising anenclosure which encloses the cup in the cup holder so that the cup isinaccessible during adding of the heated liquid into the cup.
 41. Anapparatus for making frozen drinks from a frozen substance in a cup,wherein the substance is frozen to substantially conform to an interiorof the cup, the apparatus comprising: a cup support for receiving thecup and inhibiting rotation of the cup, the cup having a vertical axis;a rotatable blade assembly including shaving elements and aerationelements, the blade assembly moveable along the vertical axis betweenupper and lower blade positions, the lower blade position being at aheight such that when a cup is positioned in the cup support, the bladeassembly is positioned within the cup and adjacent to a bottom of thecup; a source of heated liquid; and a pump configured to direct heatedliquid from the source thereof into a cup containing a frozen substancewhen the cup is positioned in the cup support.
 42. The apparatus ofclaim 41 wherein the heated liquid and the rotatable blade assemblysimultaneously engage the frozen substance in the cup.
 43. The apparatusof claim 41, and further comprising a heater which heats the liquid toat least approximately 100° F.
 44. The apparatus of claim 41, andfurther comprising: a cup sensor for detecting a characteristic of a cupin the cup support and for producing an output corresponding to thecharacteristic of the cup; and a controller for generating a processcontrol signal which corresponds to the output produced by the cupsensor.
 45. The apparatus of claim 44 wherein the characteristic is thesize of the cup.
 46. The apparatus of claim 45, wherein the pump isresponsive to the process control signal to a dispense a volume ofliquid into the cup, the volume corresponding to the size of the cup.47. The apparatus of claim 41, and further comprising an enclosure whichencloses the cup in the cup support so that the cup is inaccessibleduring pumping of the heated liquid into the cup.
 48. An apparatus formaking a frozen drink from a frozen substance in a cup, wherein thesubstance is frozen to substantially conform to the interior of the cup,the apparatus comprising: a housing; a cup support mounted to thehousing, the cup support inhibiting rotation of the cup; a liquiddispenser having an outlet positioned to direct a predetermined amountof heated liquid into a cup positioned on the cup support; and a shaftmounted to the housing, the shaft carrying a rotatable blade havingshaving elements and aeration elements thereon, the shaft moveablerelative to the housing to carry the blade between an upper bladeposition remote from the cup support and a lower blade position adjacentto the cup support, the rotatable blade configured to, when it islowered into a cup containing frozen substance, shave the frozensubstance, mix the frozen substance with heated liquid dispensed by theliquid dispenser, and incorporate air into the resultant mixture offrozen substance and heated liquid.
 49. The apparatus of claim 48wherein the heated liquid and the blade simultaneously engage the frozensubstance in the cup.
 50. The apparatus of claim 48, and furthercomprising a heater which heats the liquid to at least approximately100° F.
 51. The apparatus of claim 48 wherein the dispenser beginsdirecting heated liquid into the cup approximately when shaving of thefrozen substance in the cup begins.
 52. The apparatus of claim 48wherein the dispenser begins directing heated liquid into the cupapproximately when the blade first contacts the frozen substance in thecup.
 53. The apparatus of claim 48, and further comprising an enclosureon the housing which encloses the cup in the cup support so that the cupis inaccessible during dispensing of the heated liquid into the cup.